Improvement in pavements



UNITED STATES ATElLJLFLQ.

ANDREW B. DEAN, OF LOUISVILLE, KENTUCKY.

IMPROVEMENT IN PAVEMENTS.

Specification forming part of Letters Patent No. 161,013, dated March 23, 1875 application filed February 6, 1875.

and for other purposes; and it consists in utilizing a substance known as candle-gum, which is the residuum from the manufacture of star candle by the process of distillation,

and mixing this substance with asphaltum in such proportions as will give to it stronger cohesive properties, and a good tough body, that 1 will be impenetrable by Water, unaffected by moisture or frost, and which will be nearly imperishable under ordinary uses.

The candle-gum is known by those acquainted with its peculiarities to possess great cohesive, durable, and preservative properties; and, when it is properly incorporated with hard mineral substances, it will make a substantial pavement without the addition of asphalt. But, as water-lime, when properly combined with sand, will, under the effects of moisture, form a more durable cement than either material would make when used alone, so it is with candle-gum when mixed with asphalt by melting them together. The candlegum supplies a most perfect and durable body and life not contained in the asphalt; and when the candle-gum is thoroughly in- Iused into the asphalt, and properly mixed with mineral substances and firmly compressed, the compound will set, and form a body possessing all the qualities above stated.

To make a good pavement, a solid foundation is a most important feature, and the following description will enable others to carry my invention into efiect: First, prepare a foundation of broken stone or coarse gravel, and fill all the lower interstices with sand or line gravel, leaving the surface irregular and rugged, to afford a better hold and a stronger connection with the surface paving. I then union between the surface paving and the foundation. I then put into a suitable vessel asphaltum and candle-gum, in such proportions as the climate and character of the work require, and heat these substances to a liquid state, and thoroughly mix with them any hard mineral substance,such as coarse gravel, broken stone, &c., with a quantity of sand.

This compound is evenly spread over the substratum or foundation and firmly pressed, so as to fill every space in the rugged surface thereof. This will hold the foundation in an unbroken body. Over this layer I spread a surface coating of coarse sand and fine gravel, or finely-broken stone, mixed with hot candlegum and asphaltum, and treated in the same manner as the intermediate coating. This final coating should be compressed while it is hot. The compression is best performed by means of a roller, the surface ofwhich should be kept moistened While in use.

My improved pavement may be made by using the candle-gum and asphalt forthe binder properly intermixed with mineral substances, either with or without the addition of another material intermixed with the candle-gum and ANDREW BARTIS DEAN.

Witnesses:

H. O. Ronns, W. SHORT. 

